OP ARTS A'SD SCIENCES. 273 



A quantity of oxides from Samarskite, sent me by Dr. Shapleigh, was 

 dissolved in cblorhydric acid, and precipitated cold by an excess of po- 

 tassic sulphate. After filtering off the double sulphates, sodic sulphate 

 was added and the solution boiled. An abundant white crystalline salt 

 was obtained. After washing with a little boiling water the double 

 salt was dissolved in cblorhydric acid, and oxalic acid added after 

 large dilution. The oxalates were converted into oxides and these 

 redissolved in cblorhydric acid and again precipitated with oxalic acid. 

 The oxalates were then analyzed. 



(121) 0.2853 gr. gave 0.1217 gr. R2O3. 



(122) 0.3889 gr. " 0.1660 gr. " 



(123) 0.5558 gr. " 0.2256 gr. C2O3. 



Atomic mass 89.55, which does not sensibly differ from the received 

 atomic mass of yttrium. From this it appears that yttria was sepa- 

 rated in quantity by one operation after the separation of the cerite 

 oxides. 



Application of the Cohaltamines to the Separation of the Oxides. — 

 Many experiments were made to determine whether the sulphates of 

 organic alkaloids would form double salts with the sulphates of the rare 

 earths which could be made available for separations. These did not 

 lead to satisfactory results, though double salts were formed in some 

 cases. It then occurred to me that the sulphates and other salts of 

 various cohaltamines, on account of their disposition to form highly 

 crystalline compounds, might be employed with advantage. Following 

 are the results of this investigation. 



A solution of sulphate of luteocobalt precipitates completely from 

 their cold solutions as neutral sulphates the four cerite earths now 

 known, namely, the oxides of cerium, lanthanum, praseodymium, and 

 neodymium. The double sulphates are beautifully crystalline, have an 

 orange-red color, and are very slightly soluble in cold water, but prac- 

 tically at least insoluble in boiling water. They are soluble in acids, 

 and sometimes crystallize from weak acid solutions. All these com- 

 pounds appear to have the same constitution, which is that of the salts 

 discovered many years since by myself, and analyzed in my laboratory 

 by C. H. Wing.* I find, however, that the constitution of both the 

 luteo- and roseo-salts may be much more accurately represented by 

 the formulas t 



* American Journal of Science and Art, XLIX. [2.] 363. 



VOL. XXVIII (n. S. XX.) 18 



